Siemens SINAMICS G130 Engineering Manual page 80

Fundamental Principles and System Description
Engineering Information
The values specified for peak voltage V
this section are the basis for selecting the correct motor insulation and therefore determine whether motors with
standard insulation or special insulation are required for converter-fed operation. This applies irrespective of whether
the low-voltage motors are supplied by Siemens or another manufacturer.
For further details about Siemens low-voltage motors, please refer to the chapter "Motors". Nevertheless, a brief
explanation of how to correctly match the motor insulation of Siemens low-voltage motors to SINAMICS drive
systems is given below as the matching criteria are especially easy to understand at this point.
Selection of correct motor insulation for Siemens series 1LA and 1LG low-voltage motors
The table below specifies the permissible voltage limits as a function of insulation system for Siemens low-voltage
motors with round-wire windings operating on supplies up to 690 V.
Winding insulation
Standard insulation
Special insulation
Permissible voltage limits for Siemens low-voltage motors with round-wire windings up to 690 V
Line supply voltage ≤ 500 V
Motors with standard insulation and a permissible voltage V
supply voltages of ≤ 500 V.
If we compare the peak values V
Infeeds / Smart Infeeds or Active Infeeds (also green lines), then we see that they are always ≤ 1500 V independent
of the reflection factor.
In braking operation with a braking unit, the upper permissible limit of 1500 V for V
(also green lines) can generally be maintained only if the reflection factor is r < 2 at line voltages of 480 V and 500 V.
This applies in the case of G130, G150, S150 and S120 Chassis and Cabinet Modules due to the drive rating of > 75
kW (as shown in diagram: Reflection factor as a function of drive rating).
Line supply voltage > 500 V to 690 V
Motors with special insulation and a permissible voltage V
supply voltages of between 500 V and 690 V.
If we compare the peak values V
Infeeds / Smart Infeeds or Active Infeeds (also yellow lines), then we see that motors with special insulation are
required for converter-fed operation on these supply systems.
In braking operation with a braking unit, the upper permissible value for V
supply voltages of > 500 V (also yellow lines) can generally be maintained only if the reflection factor is r < 2 at a line
voltage of 690 V. This applies in the case of G130, G150, S150 and S120 Chassis and Cabinet Modules due to the
drive rating of > 75 kW (as shown in diagram: Reflection factor as a function of drive rating).
Note:
All data in this section are specified on the assumption that the motor cables are directly connected to the inverter
output and no motor reactors, dv/dt filters plus VPL or sine-wave filters are used.
Using dv/dt filters plus VPL or sine-wave filters makes a critical difference to the voltage rates of rise and voltage
spikes on the motor and alters the conditions to such an extent that motors with special insulation are not required.
The use of these filters does however impose certain limitations and these are described in detail in sections "dv/dt
filters with VPL" and "Sine-wave filters".
SINAMICS Engineering Manual – May 2008
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© Siemens AG
combined with the voltage jump rise time value T
PP
Line supply voltage Phase-to-phase
V V
Line PP permissible
≤ 500 V
> 500 V to 690 V
occurring at line supply voltages of ≤ 500 V in the tables for drives with Basic
PP
occurring at line supply voltages of > 500 V in the tables for drives with Basic
PP
Phase-to-earth
V
PE permissible
1500 V 1100 V
2250 V 1500 V
= 1500 V (green line) must be used for drives with line
PP
= 2250 V (yellow line) must be used for drives with line
PP
of the special insulation of 2250 V at line
PP
given at the beginning of
r
DC link voltage
V
DCLink permissible
750 V
1125 V
at line supply voltages of ≤ 500V
PP